- ID:
- ivo://nasa.heasarc/tartarus
- Title:
- Tartarus: Reduced ASCA AGN Data (Version 3.1)
- Short Name:
- ASCA/AGN
- Date:
- 09 May 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Tartarus database contains the results of a detailed but systematic analysis of ASCA observations of active galactic nuclei (AGN). It contains source and background events files, spectra, ancillary response files and response matrices, images, and assorted light curves for a large number of ASCA AGN observations. Spectral fit results are done by automatic XSPEC fitting. This database table allows easy access to reduced AGN data for the whole community, allowing the maximum scientific return from the data. Availability of publishable light curves, images, and spectra (which can also be readily re-fitted) should be particularly valuable to astronomers with little direct experience in the reduction of X-ray data. Version 3.1 has been created by analyzing all ASCA observing sequences with targets designated as AGN, as indicated by a leading "7" in the ASCA observing sequence number. Version 3.1 contains products for all 611 observing sequences designated as AGN observations. This is a significant improvement over Versions 1 and 2. Moreover, the 611 sequences for which products are available are complete in the sense that either the target object was not detected (in which case an upper limit on GIS2 source counts is given) or the intended AGN target was detected and the data were fully analyzed. In order to obtain the most accurate background subtraction and minimize contamination from any nearby sources, version 3.1 makes more use of custom extraction regions than previous versions. It is expected that version 3.1 will be replaced when the final ASCA calibration is completed. This database table has been created by the Tartarus Team, and they, rather than Imperial College London or the HEASARC, are responsible for the contents. It was ingested by the HEASARC in August, 2005. This is a service provided by NASA HEASARC .
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Search Results
- ID:
- ivo://CDS.VizieR/II/230
- Title:
- TASS Mark III photometric survey
- Short Name:
- II/230
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Amateur Sky Survey (TASS) is a loose confederation of amateur and professional astronomers. We describe the design and construction of our Mark III system, a set of wide-field drift-scan CCD cameras which monitor the celestial equator down to 13th magnitude in several passbands. We explain the methods by which images are gathered, processed, and reduced into lists of stellar positions and magnitudes. Over the period 1996 October to 1998 November, we compiled a large database of photometric measurements. One of our results is the tenxcat catalog, which contains measurements on the standard Johnson-Cousins system for 367,241 stars; it contains links to the light curves of these stars as well.
- ID:
- ivo://CDS.VizieR/II/271A
- Title:
- TASS Mark IV patches photometric catalog, version 2
- Short Name:
- II/271A
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Amateur Sky Survey (TASS) is a loose confederation of amateur and professional astronomers. We describe the design and construction of our Mark IV systems, a set of wide-field telescopes with CCD cameras which take simultaneous images in the V and I passbands. We explain our observational procedures and the pipeline which processes and reduces the images into lists of stellar positions and magnitudes. We have compiled a large database of measurements for stars in the northern celestial hemisphere with V-band magnitudes in the range 7<V<13. This paper describes data taken over the four-year period starting November, 2001. One of our results is a catalog of repeated measurements on the Johnson-Cousins system for over 4.3 million stars. This Version 2 of the catalog corrects a systematic error in photometry as function of Declination.
- ID:
- ivo://CDS.VizieR/J/A+A/625/A59
- Title:
- tau Boo Radial velocities & astrometric data
- Short Name:
- J/A+A/625/A59
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The formation of planets in compact or highly eccentric binaries and the migration of hot Jupiters are two outstanding problems in planet formation. Detailed characterisation of known systems is important for informing and testing models. The hot Jupiter {tau} Boo Ab orbits the primary star in the long-period (P>~1000yr), highly eccentric (e~0.9) double star system {tau} Bootis. Due to the long orbital period, the orbit of the stellar binary is poorly constrained. Here we aim to constrain the orbit of the stellar binary {tau} Boo AB in order to investigate the formation and migration history of the system. The mutual orbital inclination of the stellar companion and the hot Jupiter has important implications for planet migration. The binary eccentricity and periastron distance are important for understanding the conditions under which {tau} Boo formed. We combine more than 150 years of astrometric data with twenty-five years of high-precision radial velocities. The combination of sky-projected and line-of-sight measurements places tight constraints on the orbital inclination, eccentricity, and periastron distance of {tau} Boo AB. We determine the orbit of {tau} Boo B and find an orbital inclination of 47.2^+2.7^_-3.7_{deg}, a periastron distance of 28.3^+2.3^_-3.0_au, and an eccentricity of 0.87^+0.04^_-0.03_. We find that the orbital inclinations of {tau} Boo Ab and {tau} Boo B, as well as the stellar spin-axis of {tau} Boo A coincide at ~45 degrees, a result consistent with the assumption of a well-aligned, coplanar system. The likely aligned, coplanar configuration suggests planetary migration within a well-aligned protoplanetary disc. Due to the high eccentricity and small periastron distance of {tau} Boo B, the protoplanetary disc was tidally truncated at ~6au. We suggest that {tau} Boo Ab formed near the edge of the truncated disc and migrated inwards with high eccentricity due to spiral waves generated by the stellar companion.
- ID:
- ivo://CDS.VizieR/J/ApJ/803/90
- Title:
- {tau} Cet chemical composition
- Short Name:
- J/ApJ/803/90
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- {tau} Ceti (HD10700), a G8 dwarf with mass 0.78M_{sun}_, is a close (3.65pc) Sun-like star where five possibly terrestrial planet candidates (minimum masses of 2, 3.1, 3.5, 4.3, and 6.7M_{Earth}_) have recently been discovered. We report abundances of 23 elements using spectra from the MIKE spectrograph on Magellan. We find [Fe/H]=-0.49 and T_eff_=5387K. Using stellar models with the abundances determined here, we calculate the position of the classical habitable zone (HZ) with time. At the current best fit age, 7.63_-1.5_^+0.87^Gyr, up to two planets (e and f) may be in the HZ, depending on atmospheric properties. The Mg/Si ratio of the star is found to be 1.78, which is much greater than for Earth (~1.2). With a system that has such an excess of Mg/Si ratio it is possible that the mineralogical make-up of planets around {tau} Ceti could be significantly different from that of Earth, with possible oversaturation of MgO, resulting in an increase in the content of olivine and ferropericlase compared with Earth. The increase in MgO would have a drastic impact on the rheology of the mantles of the planets around {tau} Ceti.
- ID:
- ivo://CDS.VizieR/J/ApJ/581/1194
- Title:
- Taurus-Auriga PMS stars ages and Teff
- Short Name:
- J/ApJ/581/1194
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- To understand the formation of stellar groups, one must first document carefully the birth pattern within real clusters and associations. In this study of Taurus-Auriga, we combine pre-main-sequence ages from our own evolutionary tracks with stellar positions from observational surveys. Aided by the extensive millimeter data on the molecular clouds, we develop a picture of the region's history.
21387. Taurus Catalog
- ID:
- ivo://irsa.ipac/Spitzer/Catalog/Taurus
- Title:
- Taurus Catalog
- Short Name:
- Taurus Catalog
- Date:
- 01 Oct 2018 20:27:19
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The Spitzer Space Telescope Survey of the Taurus is a Legacy III project titled, Taurus 2: Finishing the Spitzer Map of the Taurus Molecular Clouds (Taurus). The Taurus Spitzer Legacy project has mapped ≈44 square degrees of the Taurus star-formation region using the IRAC and MIPS cameras aboard the Spitzer Space Telescope. In this release, the team provides a bandmerged catalog of 269,358 point sources for the initial 70% of the survey area ("Taurus 1"). Flux densities are reported for the 3.6, 4.5, 5.8, 8.0, and 24 micron bands of IRAC and MIPS. MIPS 70 micron flux densities are also given for a small number of sources. Aperture photometry at three radii is provided for IRAC sources. PSF-fitting photometry is reported for MIPS flux densities.
- ID:
- ivo://CDS.VizieR/J/ApJS/176/457
- Title:
- Taurus dark cloud background star catalog
- Short Name:
- J/ApJS/176/457
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Normal field stars located behind dense clouds are a valuable resource in interstellar astrophysics, as they provide continua in which to study phenomena such as gas-phase and solid-state absorption features, interstellar extinction, and polarization. This paper reports the results of a search for highly reddened stars behind the Taurus Dark Cloud complex. We use the Two Micron All Sky Survey (2MASS) Point Source Catalog to survey a ~50deg^2^ area of the cloud to a limiting magnitude of Ks=10.0. Photometry in the 1.2-2.2um passbands from 2MASS is combined with photometry at longer infrared wavelengths (3.6-12um) from the Spitzer Space Telescope and the Infrared Astronomical Satellite to provide effective discrimination between reddened field stars and young stellar objects (YSOs) embedded in the cloud. Our final catalog contains 248 confirmed or probable background field stars, together with estimates of their total visual extinctions, which span the range 2<A_V_<29mag. We also identify the 2MASS source J04292083+2742074 (IRAS 04262+2735) as a previously unrecognized candidate YSO, based on the presence of infrared emission greatly in excess of that predicted for a normal reddened photosphere at wavelengths >5um.
- ID:
- ivo://irsa.ipac/Spitzer/Images/Taurus
- Title:
- Taurus 2: Finishing the Spitzer Map of the Taurus Molecular Clouds
- Short Name:
- Taurus
- Date:
- 27 Oct 2022 19:00:00
- Publisher:
- NASA/IPAC Infrared Science Archive
- Description:
- The Taurus Spitzer Legacy project has mapped ≈44 square degrees of the Taurus star-formation region using the IRAC and MIPS cameras aboard the Spitzer Space Telescope.
- ID:
- ivo://CDS.VizieR/J/AJ/159/273
- Title:
- Taurus members & nonmembers with K2 data
- Short Name:
- J/AJ/159/273
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present an analysis of K2 light curves (LCs) from Campaigns 4 and 13 for members of the young (~3Myr) Taurus association, in addition to an older (~30Myr) population of stars that is largely in the foreground of the Taurus molecular clouds. Out of 156 of the highest-confidence Taurus members, we find that 81% are periodic. Our sample of young foreground stars is biased and incomplete, but nearly all stars (37/38) are periodic. The overall distribution of rotation rates as a function of color (a proxy for mass) is similar to that found in other clusters: the slowest rotators are among the early M spectral types, with faster rotation toward both earlier FGK and later M types. The relationship between period and color/mass exhibited by older clusters such as the Pleiades is already in place by Taurus age. The foreground population has very few stars but is consistent with the USco and Pleiades period distributions. As found in other young clusters, stars with disks rotate on average slower, and few with disks are found rotating faster than ~2days. The overall amplitude of the LCs decreases with age, and higher-mass stars have generally lower amplitudes than lower-mass stars. Stars with disks have on average larger amplitudes than stars without disks, though the physical mechanisms driving the variability and the resulting LC morphologies are also different between these two classes.
